This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The overall goal of this project is to examine the physilogical and metabolic effects of a 16-week circuit-training (strength training + aerobic activites) program, with and without behavioral component utilizing motivational interviewing, in 45 overweight Latina adolescent girls (~14-18 years of age). We hypothesize that the circuit training intervention will reduce brest cancer biomarkers by reduing circulating hormones and ovulation frequency, and improve both insulin sensitivity and adiposity.